1. Technical Field
The present invention relates to a separation method capable of providing an economically satisfactory separation and recovery efficiency or a removal efficiency, and of providing a concentration rate of an intended component with a sufficient level that withstands practical use thereof, in a case of carrying out separation and recovery of an intended material or carrying out separation and removal of an unnecessary component, from powders of various minerals or from powders of intermediate products or wastes discharged from a variety of industries, by using static electricity or magnetism.
2. Description of Related Art
As a method of carrying out separation and recovery of an intended material from powder containing particles with different components or materials, carrying out removal of an unnecessary material, or carrying out concentration of the intended material, there are conventionally employed various methods such as specific gravity separation, magnetic separation, and electrostatic separation, by using a difference in physical or physicochemical properties such as a specific gravity, magnetic properties (magnetism), electrical properties (dielectric constant, conductivity, and electrostatic property) of those particles. Selection from among those methods is determined based on the difference in properties between the intended material to be separated and recovered or concentrated, and the remaining unnecessary material. However, in those methods, conventionally, the separation and recovery efficiency or the concentration rate of the intended material is low in many cases, which results in a limited practical use in industry.
On the other hand, in recent years, a high emphasis is placed on separation and recovery or concentration of remaining useful materials, for dealing with depletion of resources, particularly, useful minerals, for effective use thereof, and for use and recycling of a by-product or wastes discharged from various industries. There is a strong demand for the separation and recovery efficiency and the concentration rate that are sufficient for the intended material that withstands practical use, and establishment of a technology for achieving lower equipment costs and lower running costs.
Under the circumstances, in recent years, a method using electrostatic separation and a method using magnetic separation which can be achieved with lower construction costs and with lower running costs, and which have a possibility of being applied in a wide range of fields are regarded as promising methods. However, in the related art, the separation and recovery efficiency and the concentration rate of the intended material is at a low level, and are not developed to a practical level.
For example, as a method using electrostatic separation, there are known technologies as disclosed in JP 2004-243154 A and in WO 2002/76620.